// Looking at serial on the scope
// Trace 1 shows a 300 baud 8N1 serial line slowly counting through 
// a 0x00-0xff progression, triggered on the falling edge of the start bit 
// Trace 2 shows the state of the LED_BUILTIN blink at the time of the serial send
// trace 3 shows the serial communications to the terminal

/*
  Uno with Scope https://github.com/Dlloydev/Wokwi-Chip-Scope
        and https://github.com/Dlloydev/Wokwi-Chip-PWM
        and https://github.com/drf5n/Wokwi-Chip-FrequencyCounter

  Wokwi Uno https://wokwi.com/projects/390819301187622913
  Wokwi Nano https://wokwi.com/projects/426440872904255489
  Wokwi Mega: https://wokwi.com/projects/390819455604080641
  Wokwi ESP32: https://wokwi.com/projects/408508221519641601
  Wokwi ESP32S3 https://wokwi.com/projects/404720144387009537

  See also https://wokwi.com/projects/359331973918199809

*/

/*

  Running Blink.ino
  Turns an LED on for one second, then off for one second, repeatedly.

  Most Arduinos have an on-board LED you can control. On the UNO, MEGA and ZERO
  it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN is set to
  the correct LED pin independent of which board is used.
  If you want to know what pin the on-board LED is connected to on your Arduino
  model, check the Technical Specs of your board at:
  https://docs.arduino.cc/hardware/

  modified 8 May 2014
  by Scott Fitzgerald
  modified 2 Sep 2016
  by Arturo Guadalupi
  modified 8 Sep 2016
  by Colby Newman

  This example code is in the public domain.

  https://docs.arduino.cc/built-in-examples/basics/Blink/
*/

#include <SoftwareSerial.h>
//#include <SoftwareSerialTX.h>

const byte RX1=3;
const byte TX1=2;
const long MyBaud=300;
const long DelayMs = 100;
const uint8_t MaxReps= 0;

SoftwareSerial mySerial(RX1,TX1); // RX, TX
//SoftwareSerialTX mySerial(TX1); // TX

// the setup function runs once when you press reset or power the board
void setup() {
  Serial.begin(9600);
  mySerial.begin(MyBaud);
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(TX1, OUTPUT);
  Serial.print("BitTime:");
  Serial.print(1000.00/MyBaud,4);
  Serial.print("ms");
  Serial.print(" ByteTime:");
  Serial.print(1000.00*9/MyBaud,4);
  Serial.println("ms");
}

uint8_t ch =-3;
uint8_t rep =0;

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);  // turn the LED on (HIGH is the voltage level)
  delay(2);                      // wait for a second
  mySerial.write(ch);
  if(true || !isPrintable(ch)){
    //Serial.write(ch);
    Serial.print("0x");
    Serial.print(ch,HEX);
  } else {
    Serial.print(ch);
    Serial.print(char(ch));
  }
  Serial.print(",");
  digitalWrite(LED_BUILTIN, LOW);   // turn the LED off by making the voltage LOW
  if(rep-- == 0 ){
     ch+=1;
     rep = MaxReps;
  }
  if(ch==0)Serial.println();
  delay(DelayMs);                      // wait for a second
}